This is probably Dad on the nest. From what I've read, doves, unlike other birds, incubate their eggs continually for the two weeks or so it takes them to hatch, with the male generally taking the day shift and the female the night. The squabs will be fed by mom and dad with "crop milk" (produced by glands in the parents' throats) and regurgitated seed for another two weeks before they leave the nest. (Bleah!) This relatively short 28-day nesting cycle allows them to attempt multiple broods in a season, which works to the species' advantage, as their lifespan is only about a year and a half.
Hey! It's almost two weeks since the nest was built; soon there will be young'uns!